A block plank is a thick sawn timber board, typically 50 mm or more in thickness, used where substantial strength and load-bearing capacity are required. It is heavier and more rigid than standard planking and is often employed in temporary works, heavy-duty flooring, and structural timber construction.
Characteristics
Block planks are distinguished from ordinary boards and planks primarily by their thickness. While a standard plank may be 20-38 mm thick, a block plank starts at around 50 mm and can reach 100 mm or more. The width varies but commonly ranges from 150 to 300 mm. They are usually sawn from softwood species such as spruce, pine, or Douglas fir, although hardwood block planks are used in specialised applications like marine construction or heavy industrial flooring.
The increased cross-section gives block planks considerably higher bending strength and stiffness compared to thinner boards. They can span greater distances between supports and carry heavier loads, making them suitable for applications where thinner timber would flex or fail.
Application
In construction, block planks serve a variety of purposes. They are commonly used as scaffold boards, temporary access decking on building sites, formwork supports, and heavy-duty shelving in warehouses. In traditional timber-frame construction, thick block planks may function as floor decking laid over widely spaced joists.
Block planks also find use in agricultural buildings, bridge decking, and outdoor structures like loading docks. When used outdoors or in damp conditions, they are typically pressure-treated with preservative to resist rot and insect attack. Proper stacking with spacer sticks is important during storage to allow air circulation and prevent warping.
Related terms
- Scaffold board
- Timber joist
- Formwork
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